Campbell Scientific's latest datalogger is designed to take on a multitude of applications. Looking at the CR1000, one can see the resemblance of its tough predecessor, the CR10X. The electronics are protected and electromagnetically shielded in a stainless steel can. To keep the per-unit cost low for remote stations or large networks, the wiring panel does not have a built in keyboard or display. Designed to take on the functionality of the CR10X and more, the CR1000 is not merely an upgrade. Its communications capability and support for intelligent sensors set it apart.
The CR9000X, CR5000, and CR200-series share the CRBasic programming language. Pakbus communications have been available in the CR23X, CR10X, and CR200 dataloggers. The CR1000, in conjunction with its support software, will extend those benefits to more users.
Hardware
The CR1000 is Campbell Scientific's flagship datalogger. For communications and data storage there is an RS232 port, a CS I/O port, and a parallel peripheral port. For measurement and control there are eight differential/16 single-ended analog inputs, three switched excitation channels, two pulse inputs, 12 grounds, six power grounds, one +5 V terminal, two 12 V terminals, one switched 12 V terminal, and eight digital I/O terminals.
The analog inputs offer incremental improvements from the CR10X. The CR1000 has two more differential channels. A ±5 V range allows inputs of sensors with a 5 V output without the use of a voltage divider. On voltage ranges up to ±250 mV, a full line cycle integration option provides improved rejection of 50 or 60 Hz noise.
As an indication of the speed, at the minimum scan interval of 10 ms (100 Hz measurements) the CR1000 can measure and store the results from all eight differential channels (800 measurements per second). At the same scan interval, it could measure and store results from 13 single-ended channels (1300 measurements/s).
Digital I/O ports
Campbell Scientific designed an application-specific integrated circuit (ASIC) for the CR1000. Initially, the custom ASIC was evaluated as a way to save some costs in the signal conditioning circuitry for the pulse inputs and power supplies. As its makers proceeded with the ASIC design, they found more ways to use it. For example, the ASIC controls the measurement sequence and timing, freeing up the CPU for faster processing and data storage. The two pulse-count inputs and all eight digital I/O ports have the ability to count pulses using 24-bit counters that can handle the maximum input frequencies without over-ranging. Earlier dataloggers had 16-bit counters that needed special treatment for higher frequencies.
The ASIC also handles serial communications on the CS I/O, the RS232, and the digital I/O ports. The hardware will support timing between signal transitions and between transitions of different signals, similar to SDM-INT8 functionality.
This edge timing is not supported in the first release of the CR1000 Operating System, but when the OS with timing support is released it can be downloaded into existing CR1000s.
The two pulse count inputs can count switch closures, 'high frequency' signals, and low-level AC signals. The digital I/O inputs can count switch closures and 'high frequency' signals without additional signal conditioning. The digital I/O ports can also be used to count low-level AC signals with the addition of the LLAC4 module.
In addition to serial communications offered by the 9-pin CS I/O and RS232 ports, the eight digital I/O terminals can be configured in pairs (transmit and receive) of up to four communications (COM) ports.
These COM ports support serial communication from 300 to 115200 baud, and can be used to:
* Collect data from 'smart' sensors.
* Communicate between dataloggers.
* Connect to another modem or network link.
* 'Pass through' communications from a modem on the CS I/O or RS232 port to a digital camera or other device connected to a COM port.
The peripheral port is a parallel communications port introduced with the CR1000. The CFM100 CompactFlash Module will be the first peripheral supported by the port. The CFM100 will expand CR1000 memory using compact flash media.
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